Signal detection contactor and signal correcting system

ABSTRACT

A signal detection contactor has a contactor main body and a plurality of coaxial bodies. Each coaxial body includes a core wire. The core wire is used for coming into contact with a probe of a prober and for receiving a signal transmitted from a tester, in order to calibrate a phase difference among signals transmitted through a plurality of probes.

This application is a 371 PCT/JP03/02576, filed 5 Mar. 2003.

This application is based upon and claims the benefit of priority fromthe prior Japanese Patent Application No. 2002-114950, filed Apr. 17,2002, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a signal detection contactor and signalcalibration system used when calibrating a signal for testing theelectrical characteristics of, e.g., a high-speed device.

BACKGROUND ART

In the manufacturing process for a semiconductor device or the like,when testing the electrical characteristics of a target test object (tobe referred to as “device” hereinafter) formed on a wafer-like substrate(to be merely referred to as “wafer” hereinafter) W, a prober shown in,e.g., FIGS. 4A and 4B, is used. The prober has a loader chamber 1 andprober chamber 2. A test head T for a tester 27 is pivotally arranged ona head plate 9 arranged on the prober chamber 2. The test head T iselectrically connected to a probe card 7 and a plurality of probes 7Aprovided to the probe card through a performance board (not shown). Atest signal transmitted from the tester 27 is sent to the probes 7Athrough the test head T and the performance board. The probes 7A applytest signals to the electrode pads of a device formed on the wafer W.Thus, the electrical characteristics of the device, e.g., a plurality ofsemiconductor devices (chips), formed on the wafer W are tested.

The test signals are transmitted from the tester 27 to the probes 7Athrough signal lines. If all the signal lines and the probes 7A have thesame physical characteristics, the test signals can be correctlytransmitted to the plurality of probes 7A through the performance board.Therefore, the probes 7A can apply the test signals to the electrodepads with the same phase, so that the device can be tested correctly.Due to a slight difference in the manufacturing process, however,sometimes the physical characteristics of the respective signal linesand the respective probes 7A differ slightly from each other. As thetest signals are very sensitive, a slight difference in physicalcharacteristics of the probes 7A may sometimes cause, e.g., a phasedifference, among the test signals that have arrived the distal ends ofthe probes 7A. If the test signals have a phase difference or the like,it is difficult to correctly test the device.

As a technique for calibrating the phase difference of the signals, forexample, Jpn. Pat. Appln. KOKAI Publication No. 2000-352578 discloses atechnique related to a timing calibration method for an IC test device.According to the timing calibration method described in Jpn. Pat. Appln.KOKAI Publication No. 2000-352578, delay time difference among signalsfrom times at the signal generation to times at the signal arrival dueto difference in the length of signal transmission lines of the IC testdevice can be calibrated. Due to the manufacturing process or the like,however, if the physical characteristics of the signal lines or the likediffer slightly, and accordingly the timings at which signals of therespective signal lines arrive differ, this difference in timing cannotbe calibrated. This timing calibration method is concerned with an ICtest device. In the prober, the arrival times of signals, whichtransmitted from the tester to the probe card, differ depending on thephysical characteristics of the respective signal lines. It isrecognized that, in order to calibrate the arrival times of therespective signals, the signals must be detected at the distal ends ofthe respective probes. It is, however, difficult to detect the signalsat the distal ends of the probes, and accordingly it is difficult todetect and calibrate the difference among the plurality of test signals.

DISCLOSURE OF INVENTION

The invention of the present application has been made to solve at leastone of the problems described above. According to one aspect of thepresent invention, there is provided a signal detection contactor whichcan reliably detect a signal from the distal end of a probe. Accordingto another aspect of the present invention, there is provided a signaldetection contactor which has excellent RF characteristics and canobtain a stable contact state with a probe.

According to a further aspect of the present invention, there isprovided a signal calibration system which can detect and calibratesignals from the distal end of probes.

The further problems and advantages of the present invention will bedescribed hereinafter, part of which is obvious from the disclosurethereof, or will become apparent by practicing the present invention.The objects and advantages of the present invention can be realized bymeans particularly indicated herein and a combination thereof.

According to the first aspect of the present invention, there isprovided, in an apparatus which applies a signal from a signal source toa target through at least one terminal, a signal detection contactor toreceive and detect the signal to be applied by the terminal to anelectrode of the target by coming into contact with the terminal.

The signal detection contactor based on the first aspect of the presentinvention can comprise either one of the following preferablearrangements (1) to (9), or a combination of any plurality of thefollowing arrangements.

-   (1) The signal detection contactor comprises a contactor main body    and at least one coaxial body. The coaxial body comprises a core    wire. The core wire comes into contact with the terminal to receive    a signal.-   (2) In a prober which causes a plurality of probes and a plurality    of electrodes of a target test object to come into contact with each    other, and tests electrical characteristics of the target test    object based on a signal from a tester, the signal detection    contactor detects test signals applied by the tester to each    electrode through each probe. The probe is a terminal, the device is    a target, and the tester is a signal source.-   (3) The signal detection contactor comprises a plurality of coaxial    bodies, and is used for calibrating a phase difference among signals    transmitted through the plurality of probes.-   (4) The signal detection contactor includes a conductor surface with    which at least probes other than the probe which comes into contact    with the core wire is to come into contact.-   (5) The contactor includes an insulator which covers an outer    surface of an upper end face of a core wire which is to come into    contact with a probe.-   (6) The core wire is made of a hard metal.-   (7) The core wire is made of tungsten carbide.-   (8) The core wire comprises an upper end face which comes into    contact with a probe, and a main body portion continuous to the    upper end face. The diameter of the upper end face is smaller than    that of the main body portion.-   (9) An upper end face of a core wire which is to come into contact    with a probe on a surface of the contactor main body is    dull-finished.

According to another aspect of the present invention, in a prober whichtransmits signals through a plurality of probes to test electricalcharacteristics of a target test object, there is provided, a signalcalibration system to calibrate a signal applied by at least one probeon an electrode of the target test object. The signal calibration systembased on this another aspect of the present invention can furthercomprise at least one of the following preferred arrangements (1) to(11), or an arrangement as a combination of any plurality of thefollowing arrangements.

-   (1) A signal calibration system comprises a signal detection    contactor (the signal detection contactor including a contactor main    body and at least one coaxial body comprising a core wire, the core    wire coming into contact with a probe to receive a signal    transmitted from the probe) and a signal calibration unit which    calibrates a signal received by a core wire of a coaxial body.-   (2) The signal calibration system comprises a moving mechanism to    move a signal detection contactor in a horizontal direction and an    elevating mechanism to move the signal detection contactor in a    vertical direction.-   (3) The signal calibration system comprises a signal detection body    which detects a signal from a coaxial body of a signal detection    contactor.-   (4) The detection contactor includes a plurality of coaxial bodies.    The coaxial bodies are arranged in the contactor main body with a    layout different from that of the plurality of probes.-   (5) A core wire provided to the coaxial body comes into contact with    a probe on an upper end face which is exposed to an outer surface at    least at one portion of a surface of a contactor main body.-   (6) The contactor includes a plurality of coaxial bodies each    including a core wire corresponding to a type of the signal.-   (7) The contactor has an insulator which covers an outer surface of    an upper end face of a core wire which is to come into contact with    a probe.-   (8) The core wire is made of a hard metal.-   (9) The core wire is made of tungsten carbide.-   (10) The core wire comprises an upper end face which is to come into    contact with a probe, and a main body portion continuous to the    upper end face. The diameter of the upper end face is smaller than    that of the main body portion.-   (11) An upper end face of a core wire which comes into contact with    a probe on a surface of the contactor main body is dull-finished.

According to another aspect of the present invention, there is provided,in a prober which transmits signals through a plurality of probes totest electrical characteristics of a target test object, a method ofcalibrating a test signal in a signal calibration system to calibrate asignal applied by at least one probe to an electrode of the target testobject. This method comprises the following. (a) At least one probe andat least one core wire of a coaxial body provided to a signal detectioncontactor are brought into contact with each other. (b) A signal istransmitted from a tester provided to the prober to a probe which is incontact with a core wire. (c) The signal transmitted to the probe isapplied to the core which is in contact with the probe. (d) The signalapplied to the core wire is transmitted to the tester. (e) The signalapplied to the core wire and transmitted to the tester is calibrated bythe tester. (f) The steps (b) to (e) are repeatedly performed tocalibrate signals transmitted to the other probes.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are incorporated in and form a part of thespecification to show a preferable embodiment of the present invention.The drawings are used in the description of the present invention by wayof general description made above and a detailed description concerningthe preferable embodiment to be described below.

FIG. 1 is a conceptual view showing a signal calibration systemaccording to one embodiment of the present invention.

FIGS. 2A and 2B are views showing an embodiment of a contactor accordingto the present invention, in which FIG. 2A is a sectional view of thesame, and FIG. 2B is a plan view of the same.

FIG. 3 is an enlarged sectional view of the coaxial body portion of thecontactor shown in FIG. 2A.

FIGS. 4A and 4B are views showing an example of a prober, in which FIG.4A is a partially cutaway front view of the front surface of a prober,and FIG. 4B is a plan view showing the interiors of a loader chamber andprober chamber.

BEST MODE FOR CARRYING OUT THE INVENTION

The invention of the present application provides, in an apparatus whichapplies a signal from a signal source to a target through at least oneterminal, a signal detection contactor to receive and detect the signalto be applied by the terminal to the electrode of the target by cominginto contact with the terminal, and a signal calibration system and amethod of calibrating a signal to calibrate the signal applied to thetarget. Various types of apparatuses are used as the apparatus whichapplies a signal to a target. To describe the invention of the presentapplication more specifically, a prober which tests the electricalcharacteristics of a device will be described.

The signal calibration system according to the invention of the presentapplication will be described by way of the embodiment shown in FIGS. 1to 3. In this embodiment, the signal detection contactor and the methodof calibrating a signal according to an embodiment of the invention ofthe present application will also be described. As shown in FIG. 1, asignal calibration system 10 according to this embodiment detects andcalibrates a signal for testing a device in a prober 20. The signalcalibration system 10 can use a signal detection contactor 12 describedabove. The prober 20 has an elevatable stage (e.g. main chuck) 22 in aprober chamber 21. The stage 22 can horizontally move in X and Ydirections by an X-Y table 23. A probe card 24 is arranged above thestage 22. The probe card 24 can be electrically connected to a test head26 through a performance board 25. The test head 26 can also beconnected to a tester 27. The probe card 24, performance board 25, testhead 26, and tester 27 can be electrically connected to each otherthrough 50 Ω coaxial cables 28. When testing a wafer, an alignmentmechanism (not shown) and the X-Y table 23 cooperate with each other toalign the electrode pads of a device formed on the wafer placed on thestage 22 with probes 24A provided to the probe card 24. After that, thestage 22 moves upward in the Z direction. The electrode pads of thewafer and the probes 24A are brought into electrical contact with eachother. The electrical characteristics of the wafer are tested based on aplurality of test signals from the tester 27.

The signal calibration system 10 according to this embodiment maycomprise the signal detection contactor (to be merely referred to as“contactor” hereinafter) 12, the signal calibration unit 27 forcalibrating the signals, an elevating mechanism (e.g., elevatingcylinder) 11 added to the X-Y table 23, and a signal detection body (tobe referred to as “signal detection board” hereinafter) 13.

The contactor 12 is fixed on a support 11A at the upper end of the rodof the elevating cylinder 11, and can come into electrical contact withthe probes 24A of the probe card 24. The signal detection board 13 canbe electrically connected to the contactor 12, and to the signalcalibration unit through a connector 14.

The signal calibration unit 27 outputs signals to the probes through thetest head 26. The signal detection board 13 obtains the waveforms of thesignals through the contactor in electrical contact with the probes.Hence, delay times and voltage levels of the signals can be detected.

The signal detection board 13 can also have the function of outputtingsignals. When the signal detection board 13 outputs signals, the testhead 26 serves as a signal detection board.

The signal calibration unit 27 calibrates, e.g., the levels andwaveforms of the signals and a phase difference among the signals. Inthis embodiment, a tester is used as the signal calibration unit 27, butthe present invention is not limited to this. The signal calibrationunit 27 may be provided independently of the tester, or can be builtinto the tester. In the following description, the signal calibrationunit 27 serves as the tester 27. The contactor 12, signal detectionboard 13, connector 14, and tester 27 can be connected to each otherthrough 50 Ω coaxial cables 29.

FIG. 1 is a view in which the contactor 12 is in contact with the probes24A. When testing the wafer, the upper surface of the contactor 12 canbe set at a position lower than the wafer stage surface of the stage 22,so it will not hinder wafer test.

As shown in, e.g., FIGS. 2A and 2B, the contactor 12 of this embodimentcan have a contactor main body 121, and at least one coaxial body 122provided to the contactor main body 121. The coaxial body 122 cancomprise a core wire 122A. When the core wire 122A comes into contactwith a corresponding probe 24A, a test signal arriving the distal end ofthe probe 24A can be received. The signal received by the core wire 122Acan be transmitted to the tester 27 through the signal detection board13 and connector 14 shown in FIG. 1. The tester 27 can calibrate thephase differences among the plurality of signals transmitted to it. Thetester 27 can also calibrate the waveforms and signal levels of therespective signals.

As shown in FIG. 2, the contactor main body 121 can be made of, e.g., ametal. In this embodiment, a rectangular structure made of an iron alloyis employed. One or a plurality of coaxial bodies 122 can be provided tothe contactor 12. The contactor of this embodiment has three coaxialbodies. The three coaxial bodies 122 are used as a driver coaxial body,a comparator coaxial body, and a waveform monitor coaxial body,respectively. The plurality of coaxial bodies 122 can be arranged in thecontactor main body 121 with a layout different from that of theplurality of probes. In this embodiment, the coaxial bodies 122 can bearranged obliquely on one side surface of the contactor main body 121,as shown in FIG. 2B. When the coaxial bodies 122 have an oblique layout,they can be shifted from the layout of the probes 24A. If the layout ofthe coaxial bodies and the layout of the probes are shifted from eachother, when one coaxial body 122 is in contact with one probe 24A, theother coaxial bodies 122 can be prevented from coming into contact withthe other probes 24A.

The core wire 122A provided to the coaxial body 122 of FIG. 3 has itsupper end face 122G exposed at least at one portion of the surface ofthe contactor main body, so that it can come into contact with thecorresponding probe 24A. The position of the core wire 122A is notlimited to this, and the core wire 122A can be arranged at any positionwhere it can come into contact with the corresponding probe 24A on thecontactor.

When a test signal deriving portion is formed as the coaxial body 122, acontactor 12 having excellent frequency characteristics with which evena high frequency will not attenuate easily can be provided.Consequently, even an RF signal can be calibrated reliably. The flatsurface of the contactor main body 121 can have a size of, e.g., a 40-mmsquare.

A cutout portion 121A can be formed in one side surface (right surfacein FIGS. 2A and 2B) of the contactor main body 121. A plate-like portion121B can be formed on the upper side of the cutout portion 121A. Forexample, the three coaxial bodies 122 can be buried in the plate-likeportion 121B. The cutout portion 121A can accommodate coaxial connectors124 connected to the coaxial bodies 122. When a cutout portion is formedin the contactor main body, coaxial bodies and the like can be arrangedeasily. Flanges 121C are formed on the left and right of (top and bottomin FIG. 2B) the contactor main body 121. The contactor main body 121 canbe fixed to the support 11A of the elevating cylinder 11 through theflanges 121C.

The contactor can have a conductor surface 125 with which at least partof a probe other than the probe which comes into contact with the corewire 122A comes into contact. The conductor surface 125 can be formedby, e.g., nickel plating performed on the surface of the contactor mainbody 121. Thus, impedance matching can be performed between the probe24A in contact with the core wire 122A and a probe 24A in contact withthe nickel-plated 125 portion.

The signals are transmitted from the tester 27 to the probe card 24through the coaxial cables 28. However, the probes 24A themselves cannothave coaxial structures. Therefore, when the signals are transmittedfrom the probe card 24, signal reflection may occur on the distal endsof the probes 24A due to impedance mismatching, causing disturbance inthe signal waveforms. Concerning this, according to the presentinvention, a test signal probe 24A and a ground probe 24B can bearranged on the probe card 24. The ground probe 24B of the coaxial cable28 can be arranged adjacent to the test signal probe 24 of the coaxialcable 28 corresponding to this ground probe 24B. Therefore, when thesignal probe 24A comes into contact with the upper end face 122G of thecore wire 122A provided to the contactor main body 121, the ground probe24B comes into contact with the nickel-plated portion of the contactormain body 121 simultaneously. Thus, an impedance of 50 Ω can bemaintained in the entire signal transmission lines, and signalreflection or the like from the distal ends of the other probes 24A(probes other than the probe 24A in contact with the contactor 12) canbe prevented. That surface of the contactor main body 121 with which theother probes 24A come into contact is grounded to the ground of thecoaxial connectors 124 connected from the contactor main body 121 to thetester 27. Thus, signals can be detected more correctly.

FIG. 3 is an enlarged sectional view of the buried portion of thecoaxial body 122 in FIG. 2A. This coaxial body 122 may have the corewire 122A, an insulating layer 122B, and a conductor layer 122C. Theinsulating layer 122B covers the outer surface of the core wire 122A.The conductor layer 122C covers the outer surface of the insulatinglayer 122B. Part of the core wire 122A can have a projection 122Dprojecting upward from the upper ends of the insulating layer 122B andconductor layer 122C. This core wire has the upper end face 122G to comeinto contact with the probe, and the main body portion 122A continuousto the upper end face. The diameter of the upper end face 122G can besmaller than that of the main body portion. For example, the projection122D of the core wire 122A can be comprised of a tapered portion 122Eand small-diameter portion 122F. The diameter of the tapered portion122E gradually decreases upward. The small-diameter portion 122Fprojects from the tapered portion 122E toward the upper end. In thisembodiment, the projection 122D, i.e., the upper end face 122G of thecore wire 122A, can be formed, e.g., with a diameter of 80 μmcorresponding to the size of the electrode pad of the wafer. In thismanner, since the upper end face 122G of the core wire to come intocontact with the probe can have a desired diameter, the upper end face122G can be formed in accordance with the density of the probes 24A.

Furthermore, the contactor main body 121 can have an insulator 123 forcovering the outer surface of the upper end face 122G of the core wireto come into contact with the probe 24A. For example, the projection122D can be covered with the insulator 123 on the surface layer portionof the plate-like portion 121B. When the upper end face 122G of the corewire 122A is covered with the insulator 123, the probe 24A to come intocontact with the core wire 122A and a probe 24A adjacent to it can beelectrically insulated from each other reliably. The insulator 123 canbe provided to share the axis with the tapered portion 122E. Thesurfaces of the projection 122D and insulator 123 can be flush with theplate-like portion 121B.

The core wire 122A can be made of an ultrafine-particle hard metal, andcan be made of, e.g., tungsten carbide. The insulator 123 can be made ofan insulating material such as glass. Since the core wire 122A is madeof an ultrafine-particle hard metal, it is resistant against wear bycontact with the probe 24A, thus providing a structure with excellentdurability.

Furthermore, the upper end face 122G of the core wire 122A to come intocontact with the probe on the surface of the contactor main body can bedull-finished. Then, the upper end face 122G of the core wire reliablygrips the needle point of the probe 24A, so that a stable contact statecan be obtained.

The operation will be described. Prior to wafer test using the prober20, the test signal used for wafer test is calibrated by using thesignal calibration system 10. For this purpose, first, the positioncoordinates of the three core wires 122A on the contactor 12 fixed tothe elevating cylinder 11 are input as initial setting. In this case,the images of the core wires which can be sensed by a camera providedfor the alignment mechanism (not shown) of the prober, can be input, orcan be directly input by using a ten-key pad. Subsequent to the positioncoordinates of the core wires, the position coordinates of the pluralityof probes 24A are input. In this case as well, the position coordinatescan be input by using the camera provided to the alignment mechanism, orcan be directly input by using the ten-key pad or the like. After thisinitial setting is ended, the position information of the probes 24A andcore wires 122A are transmitted to the prober 20.

In the prober 20, the alignment mechanism brings the specified probes24A and specified core wires 122A in contact with each other based onthese pieces of information. More specifically, the X-Y table 23 movesthe contactor 12 in the X or Y direction, to align the upper end faces122G of the core wires provided to the coaxial bodies 122, and theprobes 24A with each other. Subsequently, the elevating cylinder 11moves the contactor 12 upward to be higher than the stage surface of thestage 22. Then, as shown in FIG. 1, the upper end faces 122G of the corewires and the needle points of the probes 24A can come into contact witheach other. At this time, when the upper end faces 122G of the corewires 122A are dull-finished, a stable contact state can be obtainedbetween the needle points of the probes 24A and the upper end faces 122Gof the core wires 122A. Thus, contact between the needle points of theprobes 24A and the upper end faces 122G of the core wires 122A isstabilized, and the core wires 122A can reliably receive the signalsfrom the probes 24A. At this time, the probe 24A for applying a drivertest signal can come into contact with the driver core wire 122A. Theprobe 24A for applying a comparator test signal can come into contactwith the comparator core wire 122A.

With the core wires 122A and the probes 24A being in contact with eachother, the tester 27 transmits predetermined test signals to the probecard 24. The test signals arrive the probes 24A through the respectivesignal wires of the test head 26 and performance board 25, and areapplied to the core wires 122A from the probes 24A. The signals receivedby the contactor 12 are detected by the signal detection board 13, andare transmitted to the tester 27. Alternatively, the signals received bythe contactor 12 may be directly transmitted to the tester 27 anddetected by it. The test signals are transmitted through the coaxialbodies 122 in the contactor 12. Thus, even if the signals arriving theprobe card 24 are RF test signals, they can be correctly transmitted tothe tester 27. The tester 27 measures the time taken from transmissionto reception of the test signals, and analyzes the waveforms and signallevels of the received test signals, so that the respective signals canbe calibrated.

When signal analysis for one probe 24A is ended, the tester 27 repeatsmeasurement described above for all the remaining probes 24A. The tester27 compares the arrival times of all the test signals taken fromtransmission to reception, and refers to, e.g., that test signal whichhas the longest arrival time, as a reference, to equalize the arrivaltimes of the other test signals, so that the phase difference among thesignals can be calibrated. Alternatively, the tester 27 may refer to thearrival time of a desired signal to calibrate the other signals. In thismanner, the phases of all test signals can be equalized.

The present invention is not limited to the above embodiment at all. Forexample, it suffices as far as the contactor 12 has at least one coaxialbody 122. The number of coaxial bodies can be increased as necessary. Asthe material of the core wire 122A, an ultrafine-particle hard metalother than tungsten carbide can be used. To form the insulator 123surrounding the core wire 122A, an insulating material other than glasscan be used.

According to the embodiment of the invention of the present application,a signal at the distal end of a probe is detected by using a signaldetection contactor. With this arrangement, a difference in signalarrival times caused by a variation in electrical characteristics of therespective signal lines and respective probes due to a variation in themanufacturing process can be detected reliably. Thus, a signalcalibration system that can correctly calibrate a signal used for devicemeasurement can be provided.

According to the embodiment of the invention of the present application,because of the presence of the coaxial body, a signal detectioncontactor which has excellent RF characteristics and can measure asignal correctly and reliably can be provided.

According to the embodiment of the invention of the present application,since the signal detection contactor has a conductor surface, impedancematching can be obtained between a probe in contact with thecoaxial-body and a probe in contact with the contactor surface.

According to the embodiment of the invention of the present application,since a signal detection contactor and a signal calibration unit areprovided, a phase difference among test signals can be detected andcalibrated precisely.

According to the embodiment of the invention of the present application,since the plurality of coaxial bodies are arranged in the contactor witha layout different from that of the plurality of probes, a probe otherthan the target probe can be prevented from coming into contact with thecoaxial body, and the signal of the target probe can be measuredprecisely.

According to the embodiment of the invention of the present application,the core wire provided to the coaxial body has its upper end faceexposed at least at one portion of the surface of the contactor mainbody, so that it can come into contact with the corresponding probe. Theupper end face of the core wire and the conductor surface can form oneflat surface. Thus, the probe as the measurement target can come intocontact with the upper end face, while the other probes can come intocontact with the conductor surface.

According to the embodiment of the invention of the present application,an insulator covers the outer surface of the upper end face of the corewire. Thus, a probe in contact with the core wire and a probe adjacentto it can be electrically insulated from each other reliably.

According to the embodiment of the invention of the present application,the core wire is made of an ultrafine-particle hard metal. Thus, a corewire which is resistant against wear due to. contact with the probe andhas excellent durability can be provided.

According to the embodiment of the invention of the present application,the diameter of the core wire decreases from its main body portiontoward its upper end face. Thus, the upper end face of the core wire canhave a desired diameter in accordance with the density of the probes.

The upper end face of the core wire to come into contact with the probeis dull-finished. Thus, a core wire that can reliably grip the needlepoint of the probe and accordingly can obtain a stable contact state canbe provided.

Further features and modifications are easily anticipated by a personskilled in the art. Therefore, the present invention has a widerperspective, and is not limited to the specific detailed description andtypical embodiment disclosed herein. Accordingly, various modificationscan be made without departing from the spirit and scope of the generalidea of the invention defined by the appended claims and an equivalentthereof.

1. In a prober which transmits signals through a plurality of probes totest electrical characteristics of a target test object, a signalcalibration system to calibrate a signal applied by at least one of theprobes to an electrode of the target test object, said signalcalibration system comprising: a signal detection contactor, said signaldetection contactor including a contactor main body, and at least onecoaxial body comprising a core wire, the core wire coming into contactwith the probe to receive the signal transmitted from the probe; and asignal calibration unit which calibrates the signal received by the corewire of the coaxial body; wherein said signal detection contactorincludes a plurality of coaxial bodies, and said coaxial bodies arearranged in said contactor main body with a layout different from thatof said plurality of probes.
 2. In a prober which transmits signalsthrough a plurality of probes to test electrical characteristics of atarget test object, a signal calibration system to calibrate a signalapplied by at least one of the probes to an electrode of the target testobject, said signal calibration system comprising: a signal detectioncontactor, said signal detection contactor including a contactor mainbody, and at least one coaxial body comprising a core wire, the corewire coming into contact with the probe to receive the signaltransmitted from the probe; and a signal calibration unit whichcalibrates the signal received by the core wire of the coaxial body;wherein the core wire provided to the coaxial body comes into contactwith the probe on an upper end face which is exposed to an outer surfaceat least at one portion of a surface of the contactor main body.
 3. Asignal calibration system according to claim 2, wherein said contactormain body includes an insulator which covers an outer surface of theupper end face of the core wire which is to come into contact with theprobe.
 4. A signal calibration system according to claim 2, wherein thecore wire comprises an upper end face which is to come into contact witha probe, and a main body portion continuous to the upper end face, and adiameter of the upper end face is smaller than that of the main bodyportion.
 5. A signal calibration system according to claim 2, whereinthe upper end face of the core wire which comes into contact with theprobe on the surface of the contactor main body is dull-finished.